FIELD OF THE INVENTION
This invention relates to grain sweeper mechanisms which direct grain toward the center of a grain tank for collection.
It is known to provide mechanisms for sweeping or otherwise clearing grain from the floor of a grain tank. Conventional grain sweepers typically include an auger that rotates about its central axis for directing grain that is lying on the floor of the grain tank toward a central opening in the floor of the grain tank. The grain then falls through the central opening in the floor for conveying to the outside of the tank. The auger extends from the center to the circumference and is coupled with a central structure that is located near or above the central opening. The auger is pivotally coupled with this central structure for swinging about the central opening. The auger acts to direct grain toward the central opening as it gradually travels on a radius within the grain tank, and thereby travels over generally the entire floor surface of the grain tank. A power source such as an electric motor is mounted to the central structure for supplying rotational power to the auger. A drive structure is typically coupled with the auger for propelling the auger about the central opening, and typically includes floor engaging wheels or a track drive that will establish traction on the floor of the grain tank. The power source that drives the auger also supplies power to the floor engaging drive wheels or tracks which drive the auger within the grain tank.
Conventional grain sweepers typically transmit power hydraulically from the power source to the drive structure. Such mechanisms include a hydraulic pump driven by the power source, a plurality of hydraulic lines which extend along the frame of the auger from the hydraulic pump to the location of the drive structure, and a hydraulic motor mounted on the drive structure for driving the drive wheel. The long hydraulic lines tend to require a large amount of hydraulic fluid, which requires the hydraulic reservoir or tank to be relatively large. Also, the relatively long distances that the hydraulic lines extend tend to cause the fluid to incur relatively large hydraulic pressure losses as the fluid travels within the hydraulic lines. The hydraulic pumps and motors must therefore be sized large enough to compensate for the energy losses incurred in the long hydraulic lines that extend out to the drive wheels.
The drive structures of prior art grain sweepers are generally positioned behind the auger. The drive structures tend to include a floor engaging drive wheel or track positioned behind the auger. Conventional grain sweepers tend also to include structure positioned in front of the auger for engaging the floor or the grain directly in front of the auger. Some grain sweepers provide floor engaging wheels positioned in front of the auger which help stabilize the auger and hold the auger in its proper operating position and orientation as it travels through grain at the bottom of the grain tank. These wheels can obstruct grain from engaging the auger properly and can thereby interfere with the auger's proper function of directing grain toward the central opening. Some grain sweepers include agitators that are positioned in front of the auger for agitating or breaking up the compacted grain in front of the auger. These agitators tend to add to the overall cost of the grain sweeper, and can sometimes obstruct grain from properly engaging the auger.
The drive structures are typically mounted with the auger in such a way that the position of the auger with respect to the drive structure is vertically adjustable for manipulating the height at which the auger engages the grain. These mounting mechanisms tend to include a large number of parts, which tend to increase the cost of the grain sweeper, and also tend to add complexity to the adjustment process.
Some conventional grain sweepers provide an auger that is generally enclosed within a shroud or cover during operation. A plurality of openings are formed in the forward portions of the shroud which allow the auger to engage the grain as the auger travels within the grain tank. The shroud generally encloses the auger so that it is less likely that objects or a persons hands or feet will contact the auger during operation. The portions of the shroud between the openings tend to block grain from entering the shroud and engaging the auger for being directed to the central opening. Agitators in front of the auger thereby serve to direct this grain toward the openings in the shroud such that all the grain lying on the floor of the tank will be received by the auger. Other types of prior art grain sweepers do not enclose the auger within any type of shroud, but rather include a bar that extends behind the auger. The drive structure is mounted to the bar and imparts a force through the bar for propelling the auger across the floor of the grain tank.
It would be desirable to provide a grain sweeper having a drive structure that is coupled with the auger by way of a mounting structure that is simple in construction, that is easy for the operator to adjust, and that includes relatively few parts so that it is simple and inexpensive to manufacture. It would also be desirable to provide a grain sweeper with a mechanism for transmitting rotational power from the central power source to the drive structure and drive wheels in an effective and efficient manner to further reduce the cost and complexity of the grain sweeper. It would also be desirable to provide a grain sweeper that allows grain to pass easily into contact with the auger without agitators or other similar devices in front of the auger. It would be desirable for such a grain sweeper to also effectively and efficiently increase the traction provided by the drive structure. It would also be desirable for such a mechanism to include a shroud within which the auger rotates during operation.